The invention relates to a self-locking safety belt reeling device for a safety belt system in motor vehicles comprising a casing and a safety belt reeling shaft supported therein with a locking member being supported eccentrically at one end of said safety belt reeling shaft, which, depending on a radial deflection controlled by a safety belt- and/or vehicle-sensitive locking system, contacts abutments fastened at said casing and locks the safety belt reeling shaft, for which purpose the locking member is coupled to an external toothing of a control disc which on the one hand is lockable by a vehicle-sensitive system in the form of a spherical sensor and is provided, on the other hand, with the safety belt sensitive system in the form of a pivotable spring-loaded inertia mass that cooperates with a control lever, whereby the control lever is pivotable into engagement with an inner toothing provided at a bearing cup that is fixedly connected to the casing, the inner toothing corresponding to an outer toothing whereby the inner and outer toothings are freely rotatable in relation to the bearing cup and are lockable by a lever which is outwardly arranged relative to the inner and outer toothings and serves as a control means for activating and deactivating the safety belt-sensitive and the vehicle-sensitive locking system at the control disc.
A safety belt reeling device of this type is described in DE-OS 34 41 532; in the known safety belt reeling device the control means for the activation or deactivation of the safety belt-sensitive and the vehicle-sensitive locking system is provided in the form of an electro-magnet which, when excited, brings the lever, cooperating with the outer toothing that is freely rotatable in the bearing cup which is fixedly connected to the casing, into its engaging position with the outer toothing with the aid of a plunger, whereby the outer toothing becomes fixed in relation to the bearing cup due to the corresponding inner toothing, so that the inertia control system cooperating with the control disc of the safety belt reeling device is provided with a functional abutment. If the lever is out of engagement with the outer toothing that is pivotable in the bearing cup, the safety belt-sensitive as well as the vehicle-sensitive locking systems are both deactivated because in that case no functional abutment exists for the cooperation between the control disc and the inertia control system; in that position the plunger pushes simultaneously the sensor lever, that is operating with the outer toothing of the control disc of the spherical sensor, out of engagement with the control disc.
The known apparatus involves the disadvantage that the control of the activation and deactivation of the respective locking system via an electromagnet is expensive, because in addition to the translatory mechanism a special sensor control is required and must be provided for. This also involves weaknesses of the known apparatus, because in the event of either the magnet or the sensor becoming inoperative or in the event of faulty signal transmission, the function of the safety belt reeling device in respect of self-locking under operational conditions of the motor vehicle is no longer ensured if the lever is permanently out of engagement with the outer toothing.
A safety belt reeling device has been known from U.S. Pat. No. 3,862,726 in which a spring arm of a spring that loads a locking member into a locking position with an outer toothing of a respective safety belt reeling shaft rests at the safety belt coil and senses the thickness of the safety belt coil wound onto the safety belt reeling shaft. In order to avoid the resulting locking of the safety belt reeling shaft by the locking member when the safety belt is completely removed from the reeling shaft and the spring arm is completely pivoted towards the reeling shaft, additional control devices are required.
It is therefore an object of the invention to improve a safety belt reeling device having the characteristics of the aforementioned type, such that the control of the activation and deactivation of the safety belt-sensitive and the vehicle-sensitive locking system is simplified and the operational reliability of a so designed safety belt reeling device is improved.